Four students were asked to write an expression which has terms that have a greatest common factor of ab. The expressions provided by the students are shown below. Michelle
16 a + 3 b

Naomi
18 a b c minus 13 a b c

Olivia
20 a b minus 14 a b c

Peyton
15 a b c + 14 a b

Which student wrote the correct expression?
Michelle
Naomi
Olivia
Peyton